The present invention relates to turbine shrouds, and more particularly, to a method of making a metal-ceramic turbine shroud.
A composite metal-ceramic turbine shroud has been proposed in copending application of Sterman, et al., entitled "Metal-Ceramic Turbine Shroud and Method of Making the Same," Ser. No. 84,244, filed concurrently herewith. Basically, this composite metal-ceramic turbine shroud employs a ceramic sealing layer which is secured to a metal substrate through mechanical matrix bonding means, e.g., a plurality of pegs, yielding a ceramic sealing layer with desirable thermal stress characteristics.
Although such composite metal-ceramic shroud structure is satisfactory for many applications, it is also desirable to provide such a composite metal-ceramic shroud structure with desirable rub wear characteristics. More particularly, it is desirable that the ceramic sealing layer in such a shroud structure wear more easily than the more costly turbine blade tips.
It is, therefore, an object of the present invention to provide a method of constructing an improved turbine shroud structure.
Another object of the present invention is to provide such a method in which the turbine shroud structure has a ceramic sealing layer which exhibits desirable rub wear characteristics and desirable thermal stress characteristics.
It is another object of the present invention to provide such a method in which the ceramic sealing layer comprises zirconium oxide modified with magnesium oxide.